Abstrato

Exact solution for the problem of segregation of polymer spherulites

M.I.Abo El-Maaty, I.A.El-Awadi, A.M.Hamed

The problem of segregation for non-crystallizable species, as a mass transfer problem during isothermal crystallization, is considered with a suitable boundary condition for the semicrystalline polymeric materials. The velocity of the growth front of an isolated spherulite is considered to be depressed as a result of segregation during crystallization and it is assumed to be inversely proportional to the square root of time. A self-similar solution has been found and shows that the species concentration, at the growth front, increases with increasing the growth-to-diffusion ratio but it is independent on the time of crystallization. The segregated species concentration in the diffusion layer, near the growth front, increases with crystallization time, this is considered to be the reason of depressing the growth velocitywith time.